First detection of RHDV2 in Oryctolagus cuniculus breeding in eastern Slovakia

Abstract Rabbit Hemorrhagic Disease Virus (RHDV) is a highly infectious virus of the genus Lagovirus that causes rabbit hemorrhagic disease (RHD). The last type 2 variant of the virus (RHDV2) is characterized by rapid adaptation, higher virulence, and the ability to overcome partial protection provided by vaccines against the original strains. From an epidemiological point of view, it therefore poses a serious risk to both domestic and wild lagomorph populations. This paper documents the first detection of RHDV2 in the eastern Slovak region based on epidemiological and clinical analysis, pathomorphological and molecular examinations of dead domestic rabbits ( Oryctolagus cuniculus f. domesticus ) in a small farm in the Košice region. The infection caused acute deaths even in two-week-old rabbits that came from breeding females vaccinated against RHDV. Necropsy revealed mainly effusions in the serous cavities and changes in the liver and lungs, predominantly of a hemorrhagic nature. The presence of RHDV2 was confirmed in liver samples using real-time PCR (RT-PCR) and subsequent sequencing of the VP60 gene. The findings highlight the seriousness of this infection in rabbit farms, pointing to the need for adequate vaccination strategies that take into account the occurrence of currently circulating endemic strains.